The southbound lanes of Interstate 15 near Lamb Boulevard reopened just after noon Wednesday following a more than two-hour closure.
Just before 10 a.m., a car traveling northbound on I-15 rolled over through the median and into southbound lanes, said Nevada Highway Patrol Trooper Jeremie Elliott.
The driver was in critical condition, Elliott said, and the vehicles closest to the accident were stuck in between interstate exits.
North Las Vegas fire spokesman Cedric Williams said there were three vehicle occupants. The male driver, a woman and an infant. All three were transported to the hospital.
Contact reporter Annalise Porter at firstname.lastname@example.org or 702-383-0264.